Comparison of procedural success and long-term outcomes of stent thrombosis in coronary bypass grafts versus native coronary arteries

Abstract

Percutaneous coronary intervention within bypass grafts accounts for a significant percentage of total interventions. Bypass graft interventions are associated with an increased risk for stent thrombosis (ST), a condition that leads to significant morbidity and mortality. Despite this, the procedural characteristics and long-term outcomes of patients with bypass-graft ST have not been reported. The aim of the present study was to evaluate the procedural success and long-term outcomes of patients presenting with ST of coronary bypass grafts. Clinical and procedural characteristics of 205 ST cases at 5 academic hospitals were reviewed. Long-term mortality and major adverse cardiovascular events (stroke, reinfarction, and revascularization) were ascertained through review of medical records and the Social Security Death Index. Kaplan-Meier analysis was used to determine the association between ST in a bypass graft and long-term outcomes. Thirteen patients (6%) in the cohort presented with ST of a coronary bypass graft. Patients with bypass-graft ST had less severe presentations with a lower proportion of ST-segment elevation myocardial infarction (23% vs 69%, p <0.001). Despite this, ST of a bypass graft was associated with a trend toward reduced postprocedural Thrombolysis In Myocardial Infarction (TIMI) flow grade (p = 0.09), leading to lower angiographic (58% vs 92%, p <0.001) and procedural (62% vs 92%, p <0.001) success. After multivariate adjustment, bypass-graft ST was associated with increased long-term mortality (hazard ratio 3.3, 95% confidence interval 1.0 to 10.7) and major adverse cardiovascular events (hazard ratio 2.7, 95% confidence interval 1.1 to 6.9). In conclusion, ST in coronary bypass grafts is associated with reduced angiographic and procedural success as well as increased long-term major adverse cardiovascular events compared to ST in native coronary vessels.